ergo
template_blas_axpy.h
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1 /* Ergo, version 3.8, a program for linear scaling electronic structure
2  * calculations.
3  * Copyright (C) 2019 Elias Rudberg, Emanuel H. Rubensson, Pawel Salek,
4  * and Anastasia Kruchinina.
5  *
6  * This program is free software: you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation, either version 3 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program. If not, see <http://www.gnu.org/licenses/>.
18  *
19  * Primary academic reference:
20  * Ergo: An open-source program for linear-scaling electronic structure
21  * calculations,
22  * Elias Rudberg, Emanuel H. Rubensson, Pawel Salek, and Anastasia
23  * Kruchinina,
24  * SoftwareX 7, 107 (2018),
25  * <http://dx.doi.org/10.1016/j.softx.2018.03.005>
26  *
27  * For further information about Ergo, see <http://www.ergoscf.org>.
28  */
29 
30  /* This file belongs to the template_lapack part of the Ergo source
31  * code. The source files in the template_lapack directory are modified
32  * versions of files originally distributed as CLAPACK, see the
33  * Copyright/license notice in the file template_lapack/COPYING.
34  */
35 
36 
37 #ifndef TEMPLATE_BLAS_AXPY_HEADER
38 #define TEMPLATE_BLAS_AXPY_HEADER
39 
40 #include "template_blas_common.h"
41 
42 template<class Treal>
43 int template_blas_axpy(const integer *n, const Treal *da, const Treal *dx,
44  const integer *incx, Treal *dy, const integer *incy)
45 {
46  /* System generated locals */
47  integer i__1;
48  /* Local variables */
49  integer i__, m, ix, iy, mp1;
50 /* constant times a vector plus a vector.
51  uses unrolled loops for increments equal to one.
52  jack dongarra, linpack, 3/11/78.
53  modified 12/3/93, array(1) declarations changed to array(*)
54  Parameter adjustments */
55  --dy;
56  --dx;
57  /* Function Body */
58  if (*n <= 0) {
59  return 0;
60  }
61  if (*da == 0.) {
62  return 0;
63  }
64  if (*incx == 1 && *incy == 1) {
65  goto L20;
66  }
67 /* code for unequal increments or equal increments
68  not equal to 1 */
69  ix = 1;
70  iy = 1;
71  if (*incx < 0) {
72  ix = (-(*n) + 1) * *incx + 1;
73  }
74  if (*incy < 0) {
75  iy = (-(*n) + 1) * *incy + 1;
76  }
77  i__1 = *n;
78  for (i__ = 1; i__ <= i__1; ++i__) {
79  dy[iy] += *da * dx[ix];
80  ix += *incx;
81  iy += *incy;
82 /* L10: */
83  }
84  return 0;
85 /* code for both increments equal to 1
86  clean-up loop */
87 L20:
88  m = *n % 4;
89  if (m == 0) {
90  goto L40;
91  }
92  i__1 = m;
93  for (i__ = 1; i__ <= i__1; ++i__) {
94  dy[i__] += *da * dx[i__];
95 /* L30: */
96  }
97  if (*n < 4) {
98  return 0;
99  }
100 L40:
101  mp1 = m + 1;
102  i__1 = *n;
103  for (i__ = mp1; i__ <= i__1; i__ += 4) {
104  dy[i__] += *da * dx[i__];
105  dy[i__ + 1] += *da * dx[i__ + 1];
106  dy[i__ + 2] += *da * dx[i__ + 2];
107  dy[i__ + 3] += *da * dx[i__ + 3];
108 /* L50: */
109  }
110  return 0;
111 } /* daxpy_ */
112 
113 #endif
template_blas_common.h
template_blas_axpy
int template_blas_axpy(const integer *n, const Treal *da, const Treal *dx, const integer *incx, Treal *dy, const integer *incy)
Definition: template_blas_axpy.h:43
integer
int integer
Definition: template_blas_common.h:40